表 1. Patient characteristics.

患者临床特征

Characteristic	PN group (n=173)	HC group (n=40)	P
IQR: interquartile range; PN: pulmonary nodule; HC: healthy control. a Wilcoxon rank sum test; b Chi-square test; c Yates' correction.
Age/yr., median (IQR)a	45 (32, 55)	42 (33, 48)	0.39
Sex/case (%)b			0.25
Male	69 (32.4)	12 (5.6)
Female	104 (48.8)	28 (13.1)
Smoking history/case (%)b			<0.001
No	134 (62.9)	40 (18.8)
Yes	39 (18.3)	0 (0.0)
Personal tumor history/case (%)c			0.99
No	167 (78.4)	39 (18.3)
Yes	6 (2.8)	1 (0.5)
Risk stratification of PN/case (%)
Unstratified	9 (5.2)	/
Low risk	100 (57.8)	/
Moderate risk	58 (33.5)	/
High risk	6 (3.5)	/